A couple months ago I decided to build an AR15 in 7.62x39. I ordered the upper assembly and called my dealer to get me a lower, which is the part with the serial# so has to come through a licensed dealer. Strange, I could make the upper assy fire without the lower, but not the other way around. I asked him to get me the parts kit and stock too. Took a couple weeks to get the upper and then at least a month for the dealer to get the lower, he didn't get the parts kit & stock so I ordered them right away. Took almost 3 weeks to get those, got them today. So I start to assemble it, the parts kit I ordered didn't come with the trigger group my bad for not reading carefully. So I looked for something inexpensive and didn't find anything so I ordered another complete parts kit, cheaper that way & I'll have some extra parts. Hope I live long enough to get to fire it.